on 2022-09-15 08:41 AM
Usually the ambient temperature close to the engine is about 125°C but in some specific cases (like gearbox for example) we may have a maximum ambient temperature up to 160°C.
Sometimes, our customers have specific repetitive pulses with a non negligible average Power leading to junction temperature increase (due to the Thermal resistance of the package). A max junction temperature of 175°C instead of 150°C gives more margin.
Anyway, qualifying at Tj=175°C means that we perform all the reli-ability tests at 175°C (HTRB, TCT and so on).
It makes the products compatible with most of the mission profiles you may find in automotive, even the more stringent.